Ab0625 Exploring Two Decades of Therapeutic Challenges: A Monocentric Experience in Rheumatoid Arthritis Patients Battling Cancer

Background: There is currently no evidence-based framework for the utilization of biologic disease-modifying antirheumatic drugs (bDMARDs) in RA patients who develop cancer. In 2023, EULAR provided points-to-consider on the initiation of targeted therapies in patients with inflammatory arthritis and cancer. Objectives: This study aims to provide insights into the real-world utilization of bDMARDs in patients with RA following a diagnosis of solid or hematological malignancy. Methods: We conducted a retrospective observational routine-care cohort study within the rheumatology department of Cochin Hospital. The study involved from over 500 patients meeting ACR/EULAR 2010 classification criteria identified from our RA registry. These patients were monitored until January 2024, and among them, 44 individuals were found to have developed cancer during RA disease course. Exclusions were made for those with multiple cancers, non-melanomatous skin cancer, and patients who developed cancer before the RA diagnosis. The follow-up time was calculated from the index date, representing the cancer diagnosis, to the date of the last follow-up visit. Descriptive statistics were used to summarize patient characteristics, bDMARD utilization, and the time elapsed from cancer diagnosis to the initiation of bDMARD therapy. We documented patterns of biologic therapy, including the introduction, continuation, or switching of biologics, for patients using biologics before the cancer diagnosis. Results: Out of the 44 RA patients, 32 (73%) were women, with a mean age of 61±18 years at the time of cancer diagnosis. The mean disease duration until the diagnosis of malignancy was 13±10 years. The total follow-up time for the study population after the index visit was 330 patient-years (PY). Detailed demographic and clinical characteristics at the index visit are summarized in Table 1. At the index date, the baseline mean Disease Activity Score 28 with C-reactive protein (DAS28 CRP) was 2.6±1.4. All 36 patients discontinued bDMARDs and out of the 33 patients on methotrexate, 20(61%) discontinued treatment at cancer diagnosis. The DAS28 significantly increased to 3.4±1.8 (p=0.002) 6±3 months after the index date and remained stable 12±5 months after the index date (3.2±1.5). The mean dose of corticosteroids dose increased from 5±1 mg/day to 12±7 mg/day within 6 months after the index date. 23/44 started a bDMARD following cancer diagnosis based on disease activity (DAS 28 CRP): 3 maintained the same bDMARD as before the cancer diagnosis, 12 switched to a different bDMARD and 8 initiated their first bDMARD. 21/23 patients (91%) initiated the bDMARD within the first five years following cancer diagnosis, including 50% within the first year. The median time from cancer diagnosis to the first bDMARD claims was 12 months for new users and 15 months for all patients on biologic therapy. The DAS28 was higher in patients who started a bDMARD (3.9±1.7 vs. 2.8±1.7). The predominant bDMARD used following the diagnosis of cancer was Rituximab (81%), followed by TNFα inhibitors (13%), IL-6R inhibitors (9%), and Abatacept (4%). In a logistic regression analysis, the DAS28 assessed at the first visit following cancer diagnosis was the only factor with a trend for the prescription of a bDMARD (Odds ratio 1.54, 95% CI 0.94-2.51). The other factors including age, disease duration, disease severity, previous biotherapy use and cancer type & stage were not associated. Conclusion: Discontinuation of RA therapies following cancer diagnosis was associated with increased disease activity leading to the use of increased doses of corticosteroids. Disease activity was the main factor associated with the initiation of a bDMARD following cancer diagnosis, which mainly occurred within the first five years, with Rituximab being the first therapeutic option especially in patients with a history of lymphoma. In our cohort, Abatacept was used with caution. These data suggest that our practice goes in line with the recommendations of EULAR and highlight the need for further studies to address the lack of evidence in this setting. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.